Microphase-Separated Adhesive Tape for Wafer Peelability
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Solution Overview
Problem
Pressure-sensitive adhesive tapes used in semiconductor wafer processing face challenges in maintaining sufficient adhesiveness during processing while ensuring easy peelability after irradiation, leading to issues like chip fly or crack formation due to inadequate adhesive strength.
Innovation Solution
A pressure-sensitive adhesive tape with a microphase-separated structure, featuring an island portion and a sea portion with different elastic moduli, is developed using a water-dispersed acrylic polymer and active energy ray-curable resin, allowing for high adhesiveness and easy peelability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a UV-curable pressure-sensitive adhesive is used to reduce adhesive strength after irradiation, then peelability is improved, but adhesive strength during processing may become insufficient
Solution Approach 1:
The adhesive layer is segmented into multiple functional components: a polymer matrix providing base adhesion, UV-curable resin for post-irradiation strength reduction, and silane coupling agent for controlled crosslinking. This segmentation allows each component to contribute differently to the adhesive behavior before and after UV irradiation, achieving both strong bonding during processing and easy peelability afterward
Solution Approach 2:
The adhesive properties are changed by varying the composition ratios of polymer, UV-curable resin, and silane coupling agent, as well as controlling the UV irradiation dose. By adjusting these parameters, the adhesive strength can be optimized for processing while ensuring sufficient peelability after curing, resolving the contradiction between maintaining strength and enabling release
2Reliability
If pressure-sensitive adhesive strength is increased to prevent chip fly during dicing, then processing reliability is improved, but chip crack may occur during pickup due to excessive adhesive strength
Solution Approach 1:
The adhesive system transitions dynamically from a high-strength state during processing to a reduced-strength state after UV irradiation. The silane coupling agent enables controlled crosslinking that provides necessary bonding strength during dicing, then the UV-curable resin allows for subsequent strength reduction, creating a dynamic adhesive profile that adapts to different processing stages and prevents both chip fly and chip crack
Solution Approach 2:
The adhesive layer is pre-formulated with UV-curable resin and silane coupling agent before processing, establishing a potential for controlled strength modification. This preliminary preparation allows the adhesive to provide maximum strength when needed during dicing, then enables easy strength reduction for safe pickup, preventing harmful effects at both stages
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The tape provides excellent adhesiveness to semiconductor wafers during processing and ensures easy peelability without breakage, addressing the challenges of chip fly and crack formation.
Implementation Method 1
a pressure-sensitive adhesive layer formed of an active energy ray-curable pressure-sensitive adhesive, wherein a surface of the pressure-sensitive adhesive layer after active energy ray irradiation has a microphase-separated structure
Data Source
AI summary
Provided is a pressure-sensitive adhesive tape that has an excellent pressure-sensitive adhesive strength, and that can achieve both of adhesiveness to an adherend and peelability. The pressure-sensitive adhesive tape includes a base material; and a pressure-sensitive adhesive layer formed of an active energy ray-curable pressure-sensitive adhesive. A surface of the pressure-sensitive adhesive layer after active energy ray irradiation has a microphase-separated structure including an island portion and a sea portion having a storage elastic modulus higher than a storage elastic modulus of the island portion, in a storage elastic modulus mapping image obtained with an atomic force microscope.